I just got my 5D Mkiii, and have some questions about getting some CF cards. I would like to get the fastest cards that the camera can use, and I see that Lexar has a 1000X card that they rate at 150mb/sec. Sandisk rates their top card at 90mb/sec. Can the 5Diii utilize these? (I also like faster cards for speed in downloading the files.)

How many RAW files per GB have people been getting with the 5D Mkiii? Are people using 16GB, 32GB or 64GB cards? And, on average, how many RAW files do you shoot on a battery charge?

The Rob Galbraith link was very instructive. I think I'll get the Lexar 32GB 1000X based on the test results. I was going to order a pair of the 16Gb's so that if one card failed I'd have another, but the results for the 32Gb card are appreciably better and I'd save a few bucks, as well.

I have been using a 128GB SanDisk Extreme Pro (100MB/s) in the 5D Mark III and D800 . Also in a 1Ds Mark III and 1D Mark IV. Very fast and very speedy. Write speeds to SD media are the bottleneck in all of those cameras which is why Canon has gone with a dual CF approach in the 1D X and Nikon pairs the Sony XQD with a CF in the D4. Downloading spped is going to also be affected by the reader.